One of the men tasked with protecting Peyton Manning will miss more than a month for the Broncos.

Right guard Chris Kuper broke his forearm during a drill at Tuesday’s practice. Mike Klis of the Denver Post reports that Kuper will miss six weeks while he recuperates, a time frame that would keep him out of the first three regular season games.

The blow is extra painful because Kuper had just made a comeback from a serious leg injury. Kuper suffered a nasty left ankle dislocation and broke his left leg in the final week of the 2011 regular season and missed OTAs and minicamp as a result of that injury. Now he’s got another injury to deal with and the Broncos have to replace one of their better offensive linemen on the fly.

Manny Ramirez is next on the depth chart, although Klis suggests the Broncos could kick Orlando Franklin inside while starting either Ryan Harris or Chris Clark at right tackle. However they fill Kuper’s spot on the field, Denver will have a hard time replacing the production they were counting on from Kuper in the first few weeks of the season.